Electric-arc lamp



(No Model.)

J. A. PIERCE. ELECTRIC ARC LAMP.

No. 479,659. Patented July 26, 1892.

UNITED STATES PATENT OFFICE.

JONATHAN A. PIERCE, OF AUSTIN, MINNESOTA.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part Of Letters Patent N0. 479,659, dated July 26,1892.

Application filed October 15, 1891- Serial No. 208,803- (No model.)

To all whom it may concern.-

Be it known that I, JONATHAN A. Prnncn, a citizen of the United States,residing at Austin, in the county of Mower and State of Minnesota, haveinvented certain new and useful Improvements in Carbon-Feed Regulatorsfor Electric-Arc Lamps, of which the following is a specification,reference being had therein to the accompanying drawings.

My invention has for its object to provide a device whereby the feed forthe carbon electrodes of electric-arc lamps may be rendered steady, soas to avoid such sudden movements of the said electrodes as will causeflickering of the lights. To this end I provide a suitable bracket orholder, which may be attached to the frame of the lamp and to which arepivotally attached swinging arms carrying rollers pressed together by asuitable spring attached to said arms, said rollers being grooved so asto properly embrace the electrode and being covered with soft rubber orother elastic material, so as to have the proper frictional grip uponthe electrode. In order that these rubber-covered rollers may run with asuitable friction, so as to give aregular and even motion to the carbonin feeding, 1 provide a tension-spring, which serves to exert a properpressure of one of the rollers against felt washers, between which it.is held. The tension-spring encircles a threaded pin, on which is placeda regulating-nut, whereby the tension of the spring may be varied toproduce a greater or less frictional drag upon the rollers.

111 the accompanying drawings, Figures 1 and 2 are opposite views of asuitable bracket with my improved regulating device applied thereto.Fig. 3 is a side view of the same, and Fig. at is a detail sectionalview.

A denotes a bracket provided with a clamping portion A, adapted tosurround a portion of the framework of the lamp (said portion of theframework being denoted in dotted lines in Fig. 3) and to be securedthereto by means of the screws to, provided with nuts Z) and by whichthe clamping-bar 0 may be tightened against the framework. To across-bar O on the lower portion of the bracket A are pivoted two arms DD, provided at their lower ends with suitable pins d d, on which aremounted the rollers E, said rollers being pressed together to embrace acarbon electrode (denoted by dotted lines) by means of a spring F, thehooked ends of which engage suitable pins or projectionsf on the saidswinging arms. The pin (1 is made of suitable length to receiveacoil-spring and is threaded for the reception of a regulating thumb-nuth, said spring pressing against a metallic washer 1', between whichlatter and the outer face of one of the wheels E is interposed a feltwasher j, a second felt washer 7.; being interposed between said rollerand a boss or on the arm D. By varying the position of the nut on thethreaded portion of the pin (1 the pressure of the felt washers may beregulated,as may be desired, to secure any proper frictional drag uponthe roller to give a steady movement to the feed. The rollers E areprovided with a covering a, of soft rubber or other suitable elasticmaterial, which exerts a yielding pressure upon the carbon electrode,and therefore secures a proper grip action of the rollers against thesame.

I am aware that it is not broadly new to provide a regulating device forcarbon electrodes in electric arc lamps consisting of spring-pressedrollers between which the electrode runs, and I do not therefore claimthis feature, broadly; but

\Vhat I do claim, and desire to secure by Letters Patent, is

1. A carbon-feed-regulating device for electric-arc lamps, consisting ofthe combination, with the bracket A, provided with the crossbar 0, ofthe swinging arms D and D, pivoted to said cross-bar and provided withpins, the rollers E, journaled on said pins and having coverings of softrubberor other suitable elastic material to exert a proper yieldingpressure or grip action against the carbon electrode, and a spring F forforcing said rollers toward each other.

2. In an electric-arc lamp, the combination, with spring-pressed rollersbetween which the carbon electrode is placed, of friction-washersbet-ween which one of the said rollers is held, a spring for exerting aproper frictional pressure of said washers against said roller, and anadj usting-nut serving to regulate the pressure of the said spring.

8. The combination, with the bracket A, of

the swinging arms pivoted thereto and pro- In testimony whereof I affixmy signaturein vided with suitable pins, the rubber-covered presence oftwo Witnesses. rollers journaled on said pins, the spring F JONATHAN APIERCE for pressing said rollers toward each other,

5 and an adjustable tension-spring and friction Witnesses:

pads or washers to vary the frictional drag LYMAN D. BAIRD, on saidrollers. A. 0. PAGE.

